Add example of advanced init + few comments

examples/ex11_external_deps.nim

@@ -8,11 +8,11 @@ proc main() =
       add(name="LinearAlgebra")
       add("DSP")
 
+  defer: Julia.exit()
   Julia.useModule("Pkg")
   let jlpkg = Julia.getModule("Pkg")
   discard jlpkg.status()
 
-  Julia.exit()
 
 when isMainModule:
   main()

examples/ex12_advanced_init.nim

@@ -0,0 +1,80 @@
+import nimjl
+import std/[os, strformat, exitprocs]
+
+proc compileCurrentFile(curRun: static int) =
+  let cmd = getCurrentCompilerExe() & &" cpp -d:run{curRun} -o:./run{curRun}.out " & currentSourcePath()
+  debugEcho cmd
+  discard execShellCmd(cmd)
+
+proc cleanUp() =
+  var envdir = "./julia-custom-env"
+  if dirExists(envdir): removeDir(envdir)
+
+  envdir = "./julia-empty-env"
+  if dirExists(envdir): removeDir(envdir)
+
+  discard tryRemoveFile("run1.out")
+  discard tryRemoveFile("run2.out")
+  discard tryRemoveFile("run3.out")
+
+
+proc postJlInit() =
+  echo "code executed after Julia VM is initialized and env is activated but before dependencies"
+  let Pkg = Julia.getModule("Pkg")
+
+  discard Pkg.update()
+  discard Pkg.status()
+
+proc firstRunmain() =
+  ## See https://pkgdocs.julialang.org/dev/api/#Pkg.add for more info
+  Julia.init(4):
+    activate("./julia-custom-env")
+    # Call postJlInit() if it exists
+    # Call Pkg + external dependencies
+    Pkg:
+      add(name="LinearAlgebra")
+      add("DSP")
+  defer: Julia.exit()
+
+proc mainNoPkgSameEnv() =
+  ## See https://pkgdocs.julialang.org/dev/api/#Pkg.add for more info
+  Julia.init(4):
+    # activate julia venv
+    activate("./julia-custom-env")
+  defer: Julia.exit()
+
+proc mainNoPkgDifferentEnv() =
+  ## See https://pkgdocs.julialang.org/dev/api/#Pkg.add for more info
+  Julia.init(4):
+    activate("./julia-empty-env")
+  defer: Julia.exit()
+
+when isMainModule:
+  when defined(run1):
+    echo "First Run:"
+    echo "  * Pkg.status show empty deps"
+    echo "  * dependencies are downloaded"
+    echo "==================================================="
+    firstRunMain()
+    echo "==================================================="
+  elif defined(run2):
+    echo "No Pkg in init but same env:"
+    echo "  * Pkg.status show deps in projects"
+    echo "==================================================="
+    mainNoPkgSameEnv()
+    echo "==================================================="
+  elif defined(run3):
+    echo "No Pkg in init and different env:"
+    echo "  * Pkg.status show empty deps"
+    echo "==================================================="
+    mainNoPkgDifferentEnv()
+    echo "==================================================="
+  else:
+    compileCurrentFile(curRun=1)
+    compileCurrentFile(curRun=2)
+    compileCurrentFile(curRun=3)
+    discard execShellCmd("./run1.out")
+    discard execShellCmd("./run2.out")
+    discard execShellCmd("./run3.out")
+    cleanUp()
+

nimjl/glucose.nim

@@ -134,6 +134,7 @@ template init*(jl: type Julia, nthreads: int, body: untyped) =
       packages = jl_pkg_private_scope
 
   template activate(env: string) {.used.} =
+    ## Activate a Julia virtual env
     pkgEnv = string(expandTilde(Path(env)))
 
   template Embed(innerbody: untyped) {.used.} =